This book considers the impact of post 9/11 counter-terrorism laws outside of the counter-terrorism context, a process described here as ‘contagion’. It does so via a detailed empirical examination of the impact of counter-terrorism measures on the criminal justice systems of three selected EU countries with varying histories and experience of terrorism, namely, the UK, France and Poland. In particular, the book explores the synergistic relationship between counter-terrorism measures and control measures aimed at ‘ordinary’ crimes and asks what the implications are for the direction of travel of the criminal law in general. It probes the hegemonic power of terrorism and the securitisation agenda more broadly and discusses the implications for criminology as a discipline – does it, for example, have a role in social contestation of contagion? This book will be suitable for academics and students interested in political violence, terrorism and counterterrorism as well as practitioners and experts working in the area.